Zombies are real... amongst Ants anyway...

[Ilya Muromets]

I wonder, in terms of neurology or something, if it's easier for the parasites to make these invertebrate animals do certain crappy behaviors because of the fact that they're not sapient at all and are just ruled by simple programming, whereas complex creatures with complex brains are able to "think" and "reason" (not REAL reason, but still, something like that) more than invertebrates whose brains are just simple biological computers anyway. Man, how complex would it be to make a parasitic organism induce certain specific behaviors on people (aside from just increasing their tendencies towards a particular set of non-specific attributes due to neurologic effects)?

A lot of such "zombifying" parasites do seem to just jack the nervous system of their host in some way. And, well, like you said, those host nervous systems are mostly rather simple. I'm betting that it's got something to do with funky neuro-chemical manipulation more than anything. Even the sacculina, which actually changes the body layout of its host rather than just making it behave in a certain way (it makes male crabs physically female), does so through the manipulation of hormones.

To actively do the same to something as complex as a human? Assuming that it's mostly attributed to neuro-chemical manipulation, a human body's one helluva complex brew of neurotransmitters and hormones and whatnot to actively manipulate into some kind of coherent behavior. It just seems too overly complex for an organism to evolve in such a way for very little real biological gain. As for actively making one? Considering how relatively simple most genetic engineering is today, there's little chance of making anything like one of Khan's brain parasites from Star Trek any time soon, if ever.

[Shroom Man 777]

Altering neurochemicals to manipulate the host would only result in changing the mood of a person, the thought patterns, and maybe cause some resultant mental illness (schizophrenia from toxoplasmosis? possible dopamine whatevers?), likewise with the hormones. But if we engineered something that could manipulate human behaviors (and thoughts?) very specifically, in order to do so we'd also have to gain an understanding of how the human mind really worked, all its facets and mechanisms, everything completely. Because, yeah, it's so damn complex. To create something so horrible, we must fully experience the wonders of discovery, for we need to achieve ultimate knowledge and understanding! To do this, we must uncover true science! Weird science! Yes! Playing God? Hah! Playing is for children!

This means that in order to specifically understand how creatures think, or how minds and behaviors and shit works, before we progress to humans we must start off somewhere simpler, like invertebrates. Looking at how these parasites do what they do, their specific mechanisms at controlling invertebrate behavior, would lead to a greater understanding of just how invertebrate brains work. Then we can progress upwards from there. And soon, the human mind itself will be ours to mold like so much clay, soft and so pliable, to hold in our very hands and to form in whichever way we choose to, to remake it not in the image which nature so flawedly created, but to sculpt it by our own wills and through our science make it... better.

Yes, my dear Malchus. Soon we will be perfect.

[Swindle1984]

The one article posted here about cat/rat parasites that infect roughly half of all humans linked to another article speculating on the parasite affecting human culture.

Now I can't get Higurashi No Nako Koro Ni out of my head.